How to use the time zone converter
- Choose the city, date and time you're starting from.
- Every city in your list updates instantly, showing the matching local time.
- Add or remove cities to build the exact comparison you need — a +1 day or −1 day marker appears when the date differs.
Why time zones are harder than they look
Offsets aren't fixed. Many countries shift by an hour for daylight saving, and they don't all switch on the same date — for a few weeks each spring and autumn the usual gap between, say, London and New York is different from normal. Some zones are also offset by 30 or 45 minutes rather than a whole hour, like India (UTC+5:30) and Nepal (UTC+5:45). This converter uses your browser's built-in IANA time zone database, so it applies the correct historical and seasonal rules for the exact date you pick rather than assuming a fixed offset.
Benefits
- Converts one time across many cities at once, not just a single pair.
- Handles daylight saving automatically using the IANA time zone database.
- Flags when a city lands on the previous or next day.
- Add and remove cities to build the exact comparison you need.
Limitations to know
- The city list covers major zones rather than every location worldwide.
- Your chosen cities are not saved between visits.
- It converts times — it does not create calendar invitations.
Common mistakes to avoid
- Assuming a fixed hour difference year-round — DST changes it for weeks at a time.
- Forgetting that some zones are offset by 30 or 45 minutes, not a whole hour.
- Missing the +1 day marker and scheduling a call on the wrong date.
Alternatives
To count days between two dates use Days Between Dates; to count down to an event use the Countdown Timer.
Last updated: August 2026 · Reviewed by the AI Toolbox editorial team.
Frequently asked questions
Does it handle daylight saving?
Yes — it uses the IANA time zone database via your browser, so DST is applied automatically for the date you choose.
Why does one city show a different date?
Because the time difference crosses midnight. The +1 day or −1 day marker tells you it lands on the next or previous day.
Can I check a future date?
Yes — pick any date and the converter applies the DST rules that will be in force then.
Is anything uploaded?
No — all conversion happens in your browser.